Apparatus for producing pressed concrete articles

ABSTRACT

There is described a number of compressible mould dividers and edge forms for use in a concrete pressing process, and a compressible mould framework for use in the process.

United States Patent 1191 OSullivan et al.

[11] 3,822,979 1451 July 9,1974

Filed: Mar. 9,, 1971 Appl. 110.; 122,519

Related US. Application Data Continuation of Ser. No. 737,780, June 17, 1968, abandoned.

U.S. Cl 425/410, 425/DIG. 5,249/82 Int. Cl. B29c 3/00 7 Field of Search 425/357, 358, 406, 410,

425/DIG. 5, DIG. 58; 249/82 [56] References Cited UNITED STATES PATENTS 1,542,687 6/1925 Finn 425/89 1,837,996 12/1931 Queinnec 425/84 2,487,019 11/1949 Eichelberger 29/468 3,052,918 9/1962 Holmes 425/357 X 3,063,122 ll/l962 Katz 249/50 3,089,189 5/1963 Feldman et al. 425/406 X 3,237,268 3/1966 Yates 425/86 3,261,897 7/1966 Munk 265/109 3,534,439 10/1970 Haas et al. 425/195 Primary ExaminerRobert D. Baldwin Assistant Examiner--John McQuade Attorney, Agent, or Firm-Cushman, Darby & Cushman [57] ABSTRACT There is described a number of compressible mould dividers and edge forms for use in a concrete pressing process, and a compressible mould framework for use in the process.

21 Claims, 16 Drawing Figures PATENTEUJUL 91914 3.822.979

' SHEET 1 0F 4 FIG. 7.

PAH-1min JUL 91914 SHEET u 0F 4 FIG. 72.

FIG 73 439 This application is a continuation of Ser. No. 7 31 780, filed June 1'1, 1968, now abandoned. This invention relates to the pressing of concrete articles of large surface area, such as panels of concrete, reinforced or otherwise, for building or engineering purposes. A press is already known in which a wet concrete mix is fed to a mould in which the mix is levelled, for example by vibratory means; the mould is then placed between platens, one at least of which is arranged to enter the mould, and pressure is applied between the platens to force water out of the mix. Certain precautions have to be taken to avoid excessive loss of fines from the mix as the water is extruded but otherwise it is a straightforward operation and, of course, there is no limitation as to size of panel that can be produced in this way except possibly for the difficulty of achieving sufficiently even distribution of pressure over the larger areas and arrangements have already been proposed to ensure that such even distribution can be obtained. The larger the panel produced, however, the larger the size of platens required and the press assembly itself becomes commensurately more expensive. It is desirable in that case that the press should be made versatile so that it could be used for the production of smaller sizes of panel, alternatively. In the design of such presses, it is necessary to change the size of the platen that enters the mould each time that the mould size is changed. While this may not prove to be too inconvenient where small sizes are concerned, when the larger sizes are involved it becomes essential to use mechanical aids to lift and manoeuvre the various parts into position; a large overhead gantry would, for example, be required. Moreover the greater the versatility of the press, the greater the number of different parts required, the greater the expense and the more extensive becomes the storage facility for the equipment. Other drawbacks, perhaps more important than these, are the time and labour elements to be taken into consideration and it is estimated, for example, that the average time to change a platen would be at least 2 hours; this would be prohibitive when the demand is for relatively few panels of a number of different sizes.

It has now been recognised that, at least for the press that is designed to produce panels of areas in excess of, say, l square feet, the upper platen should preferably be flat all over but, even so, in order that the mould may be removed from the press, provision has to be made for the moulded article to be removed. This can be overcome by arranging, as in one prior proposal, for the edge forms of the mould which surround the lower platen to be retractable downwards to free the panel for lifting, which is usually effected by means of a vacuum lifting pad. it has been proposed to vary the size of the lower platen in such arrangements by making use of a series of sections bolted together in different combinations for which a series of edge forms of different sizes are required. While this procedure provides for versatility and carries with it the advantage of the flat all-over top platen, it still is open to all of the disadvantages above set out.

In accordance with one aspect of the invention, there is provided for use in forming concrete articles, an apparatus comprising a press having upper and lower platens, and a compressible wall member engaging between said upper and lower platens and bounding one side of an article to be pressed between said platens, whereby a relative movement between said upper and lower platens is effective to press the article and compress sajd wall member.

Conveniently the apparatus may comprise a rigid mould carried on said lower platen, said upper platen being adapted to enter said mould and said wall memher being located in said mould to sub-divide the mould into two separate regions.

Thus with the partition means of the present invention, the mould area of a mould for use with a press having a substantially flat all-over top platen may be sub-divided into smaller areas so that more than one moulded article can be produced in the one pressing operation. Where the same bottom platen is used in every adaptation of the mould, allowance must inevitably be made for entry of the top platen into the confines of the sides of the mould and it is not possible simply to introduce rigid divisions into the mould for the purposes of dividing up the mould area since the platen movement would then be prevented. The present invention avoids this difficulty because the wall members provide mould dividers of a form that will permit a reduction in height so that, as the pressing operation proceeds, the movement of the platen causes a commensurate reduction in height of the dividers.

Thus it is found that in the production of a panel of final thickness of, say, 4 in. or 8 in. the depth of filling on the mould before pressing is about 4% in. or 9% in. respectively, the. difierences being the required changes in height of the dividers. It may be said here that the alternative of providing a slot in the upper platen into which a divider could be extended during pressing is almost entirely impracticable for reasons that will be obvious to those skilled in the art.

In one form of the apparatus, the compressible wall member includes at least a portion of compressible material extending substantially from end to end of the wall member.

In another form, the compressible wall member comprises a first beam, a second beam co-terminous with said first beam, and a collapsible spacer means located between adjacent faces of said first beam and said second beam.

In a further form, the compressible wall member comprises a beam, container means defining a recess vertically adjacent a long edge of the said beam, sealing means adapted to seal said recess from ingress of material from the mould during operation, wall means adapted to present with said beam an imperforate partition surface to said material in the mould, and friction means urged by the pressure of said concrete in the mould into sealing engagement with a side face of said beam, said friction means being effective to allow a controlled motion of said beam into said recess upon the application of vertical pressure to the wall member.

The degree of compression required of the infill will be high (say 65 per cent, or more) if its initial thickness is to be kept reasonable and such an infill might have relatively short life; this need not, however, prove to be unacceptable in practice. As a precaution, in order to avoid recovery movement when the pressure is relieved, it may be necessary to introduce means for preventing separation of the rigid parts while they are still in contact with the green pressing. Such means may for example be provided by friction effects and/or spring loading; hydraulic means may also or alternatively be used for controlling the separation. If they are moved at this time, the edges of the pressing would probably be damaged and this might be disadvantageous where surface appearance was important. There would, of course, be less need for the friction device in the case of the divider using a crushable portion as distinct from an elastic body; but it would be necessary to provide a fresh portion for each pressing operation.

A further alternative construction of reducible divider involves the use of an inflatable component for the collapsible spacer means, surrounded or sandwiched by metal parts. Care will probably need to be taken in this version that the pressures exerted sideways were conveniently balanced between the wall and the concrete filling itself.

It is appreciated that when some forms of the compressible wall are used, some uncontrolled irregularities may be moulded into the wall of the pressing at the point at which the deformation occurs. ln accordance with another feature of the invention, however, it is arranged that any such irregularities occurs in a part of the edge profile that is chosen for the purpose of enabling the irregularity to be obscured from view in use of the finally prepared pressing. In practice, the choice of location and, possibly, even the shape of the irregularity would be that of the user of the pressing but it is highly probable that any irregularity could be accommodated within the thickness of any panel prepared by pressing.

Preferably, however, the apparatus includes control means effective to keep the width of the wall member substantially constant during compression of the wall.

It will be observed that the invention may be extended by the use of the principle of compressible dividers to the formation of the mould walls themselves. This renders possible the use of a flat all-over bottom, as well as top, platen for the production of pressings of area less than that of the platen.

Thus, in one embodiment there are plurality of said wall members defining a collapsible mould between said upper and lower platens. With this embodiment as pressing proceeds relative movement between the press platens causes commensurate reduction in height of the wall members. Even in this latter fonn of mould, further wall members of similar form may be provided to divide the mould area into a plurality of smaller unit areas. This is not to say that the mould for one or more smaller units cannot be accommodated within the confines of a permanent mould which is made to fit the bottom platen.

In one embodiment of the invention in which there are a plurality of the collapsible wall members defining a collapsible mould between the upper and lower platens, the apparatus includes a support structure for said compressible wall members, attachment means movably connecting said wall members with said support structure, and actuator means for said partition members such that operation of said actuator means moves said wall member relative to said support structure to define moulds of different shape between said platens.

Where mould edges of the type now proposed are used which incorporate distorting portions or projections or recesses, it will be seen that it is desirable for the mould edges to be withdrawn at right angles to the direction of pressing; otherwise there will be a distinct probability of parts of the pressing being pulled away as the edging is removed.

If, as seems probable, there is a tendency for parts of the sides of the pressing to come away with the mould edges if they are withdrawn at right angles to their lengths, then it should be arranged that at least the initial movement of the mould edges upon withdrawal, should have at least a substantial component lengthways. Thus this latter embodiment preferably includes means whereby operation of said actuator means moves said partition members at least initially substantially in a lengthwise direction. However, when the interference is broken there should no longer be any reason why the edges could not be moved substantially at right angles to their lengths.

Thus the support structure above referred to may conveniently be an outer frame, said attachment means are provided by links pivotally connected between said wall members and said outer frame, and said actuator means are provided by piston and cylinder means acting between said outer frame and end faces of said wall members.

Alternatively, by adjusting the lengths of some or all of the links, the edge portions may be used to make different sizes of mould. On the other hand, of course, different sizes of edge portions may be used to form the different mould areas. It is possible, for instance, to arrange for a whole size range, in the order of 6 feet 0 inches X 4 feet 6 inches to 20 feet 0 inches X 8 feet 6 /2 inches by the use of only three sets of edge portions. Adjustable stops determine the positions of the edge portions.

The links are preferably arranged so that, when the mould is set up to receive a concrete mix, they lie substantially at right angles to the edge portions. By that means it is possible to arrange to resist sideways pressure of the concrete filling when under compression without exerting excessive strain on the linkage. This arrangement of the linkage also ensures that movement of the edge portions is initially substantially parallel to the respective side faces of the pressing. Hydraulic, pneumatic or electro-magnetic actuation of the edge portions may be used for, or in place of, the piston and cylinder means but, whicheven is used, stops are proba bly essential to limit opening movement and also a form of lock to prevent any tendency of the edge portions to open under pressure. Other alternatives will be apparent to those skilled in the art.

In order that the invention may be more fully understood, embodiments thereof will now be described, by way of example, with reference to the accompanying drawings, of which:-

FIGS. 1 and 2 show a transverse cross-section of an edge fonn in accordance with the present invention,

FlGS. 3 and 4 show a transverse cross-section of a first mould divider in accordance with the present invention,

FIG. 5 shows a transverse cross-section of a second mould divider in accordance with the present invention,

FIG. 6 shows a transverse cross-section of another edge form in accordance with the present invention,

FIGS. 7 to 12 show transverse cross-sections of further mould dividers and edge forms in accordance with the present invention,

FIGS. 13 and 14 illustrate the operation of the edgeform shown in FIG. 12,

FIG. 15 shows a plan view of a mould framework in accordance with the present invention, and

FIG. 16 shows a detail of the framework of FIG. 15 at a particular stage of its operation.

Referring firstto FIG. 1 which shows the edge form in its fully extended position, it will be seen that the edge form includes a sliding element 10 which is held against a base portion 12 of the edge form by a clamping member 14. The element 10, base 12 and member 14, together define the surface 16 which bounds the concrete under pressure. As illustrated, the member 14 tapers (in cross-section) from the face nearer base 12 to that providing part of the surface 16. The upper edge of the member 14 is provided with an inwardly projecting flange 17 which engages with the outer surface of the sliding element 10, whilst the lower edge of the member 14 is in the form of a horizontal flange 18 profiled to present bearing surfaces 20, 21 to co-operating surfaces 22, 23 of the base 12. A sealing strip 24 is located between the surface '20 and the shoulder (25) which provides the surface 22.

The member 14 is secured to the base 12 by a bolt assembly 26 which includes a bolt 28 having one of its ends screwed into the flange l8 and the other of its ends screwed into a square nut 30. The central portion of the bolt passes through an aperture 32 in the base 12 and the nut 30 is urged away from the aperture 32 by a spring washer34 acting between a recessed face of the nut 30 and a flat washer 36 which abuts with the boundary face of the aperture. The nut 30 is held against rotation by a compression spring 38 acting between the upper face of the nut and the shoulder 40 of a plunger 42. The upper end of the plunger 42 abuts with the upper face of a slot 44 formed in the base 12 remote from the face 16 and containing the plunger 42 and the nut 30. It is to be understood that there will normally be at least two arrangements 26 in the complete side form, in which case the edge form will have an identical cross-section to that shown in FIG. 1 somewhere else along its length.

The action of the bolt assembly 26, and more especially of the spring 38 thereon, is to tend to rotate the member 14 in an anti-clockwise sense (as viewed in FIGS. 1 and 2) about the pivots provided by the engaging surfaces 20, 22, and 21, 23, thus generating a sealing pressure between the flange 17 and the cooperating surface of the sliding element 10. It will be appreciated that in operation, when the concrete in the mould is under pressure, this pressure acts on the exposed faces of the member 14 to increase the contact pressure between the surfaces 21, 23 and, by pivoting the member about this region of contact, to generate an additional sealing pressure between flange 17 and the co-operating surface of element 10.

FIG. 2 is a transverse cross-section showing the edge form in its fully compressed position and it illustrates the presence of a stepped slot 46 extending from face to face of the base 12. The slot 46 has a first portion 48 remote from surface 16 and of a larger diameter (vertically and horizontally) than the second portion 50 of the slot. A bolt 52 is provided which has one of its ends screwed into a lower portion of the element 10 and the other of its ends screwed into a nut 54 located in the slot portion 48. The central portion of the bolt passes through the slot portion 50 and the nut 54 is urged away from the slot portion 48 by a spring washer 56 acting between the nut 54 and a flat washer 58 which abuts with the boundary face of the slot portion 48. It will be noted from FIG. 2 that in its fully compressed condition, the face 16 (as viewed in FIG. 2) is symmetrical about the horizontal mid plane of the edge form. When the edge form is in its fullyextended position (as shown in FIG. 1) the bolt 52 will of .course be located at the top of the slot 46.

Referring now to FIGS. 3 and 4, FIG. 3 shows a mould divider in its fully extended position and FIG. 4 shows the same mould divider in its fully compressed position.

As will be seen from FIGS. 3 and 4, the mould divider includes a downwardly tapering top beam 100, an upwardly tapering bottom beam 102, and two wedge shaped side beams 104, 106 having inclined top and bttom faces 108, 110 engaging with the inclined faces 112, 114 of beams 100 and 102 respectively. The side beams 104, 106 are interconnected at their mid points by a tension element 116 and the top and bottom beams have their mutually adjacent faces profiled to receive the tension member when the divider is in its fully compressed condition (FIG. 4).

' The element 116 comprises two cylindrical members 118 and 120 connected together by a spring 122 and respectively secured to the side beams 104, 106. The member 120 is secured to one end of a cylindrical cover 124 for the element 116 whereas the member 118 is free to slide within .the cover 124 to allow for an increased separation of the beams 104, 106 as the divider is compressed. The weight of the upper beam 100 and the strength of the spring 122 are such that with the divider in its fully compressed state (FIG. 4), the upper beam 100 has no tendency to resume the previous position illustrated in FIG. 3.

FIG. 5 shows in its fully expanded state an alternative mould divider to that shown in FIGS. 3 and 4. In the divider of FIG. 5 a top beam 200 is separated from a bottom beam 202 by a polystyrene strip 204 located between adjacent faces of the beams 200, 202. Expanded metal mesh 207, 207' is attached to these adjacent faces and engages the upper and lower surfaces of the strip 204 to prevent the strip from slipping out of place as a result of the horizontal pressure exerted on the strip by the concrete during pressing. The strip 204 is apertured at least twice along its length, as at 205 (shown as a vertical cylindrical aperture in FIG. 5), and beam 200 is correspondingly perforated by stepped apertures such as aperture 206. At each pair of apertures 205, 206, a nut is screwed on to a bolt 224 which extends through the apertures 205, 206 and is screwed into a respective wedge member 210 located within one bore 212 of a corresponding number of bores provided on the beam 202. The wedge member 210 tapers upwardly, its sloping faces being separated from the inner surfaces of bore 212 by a ring of downwardly tapering collet wedges 214. A tension band 216 extends around the collet wedges in a groove 218 formed in their external periphery. The collet wedges 214 are downwardly biassed by a compression spring 220 between the upper faces of the wedges 214 and the lower face of a flange 222 formed on the bolt 224 below the beam 200.

As the divider is compressed, the beam 200 is moved towards the beam 202, the polystyrene strip 204 is crushed between the two beams and the wedge member 210 (and the collet wedges 214) move further down the bore 212. The wedge member 210 is locked against upward movement within the bore 212 by the wedging action of the collet wedges 214. On completion of the pressing operation, the divider is removed from the formed article and the member 210 may be tapped back into place for further use.

In another embodiment of the invention, (FIG. 6), an edge form comprises an elongated wooden member 300 of rectangular or square cross-section formed with a recess 302 (shown as a square cross sectioned recess or notch taken from one comer of member 300 and running along the length thereof in FIG. 6), also of rectangular or square cross-section, along an upper edge. In addition the member 300 is provided with a plurality of slots, such as slot 304, spaced apart along the length of the member 300 and each opening into the internal vertical face 306 of the member. The edge form is completed by an elongated expandedpolystyrene block 308 having its lower portion located in the recess 302 and presenting a face 310 lying in substantially the same plane as face 306 of member 300. This edge form is designed for use in a new method of forming pressed concrete panels with an exposed reinforcement loop and in fact FIG. 6 shows the edge member arranged for use in this method. Thus in operation, the edge form is located in place on the bottom surface 312 of a mould (not shown) and a wire reinforcement mesh (such as 314) is positioned with loop portions 316 each located in an appropriate slot 304 of the member 300. The exposed parts of the slots 304 are then sealed off around the reinforcement portions 316 by any suitable plastic material 317, such as Plasticine, and concrete mix 318 is poured into the mould to a level 320 below the top of the block 308. Pressure is then applied to the top surface of the mix until the top of the mix is depressed to a predetermined level 322 which is still above the upper surface 324 of the member 300. During pressing the block 308 is crushed by the press so at all times to be level with the top of the mix 318. Naturally, therefore, a fresh block 308 must be inserted in recess 302 prior to each pressing operation. The insert of plastic material 317 prevents concrete being pushed into the slot 304 during pressmg.

When the pressing operation has been completed, the pressed article is expelled from the mould by rams and the member 300 and the block 308 are together pulled clear of the concrete article, thus leaving the reinforcement loops exposed and the material 317 still in position within the loops. This material is manually removed from the loops and the article is then ready to be taken away, e.g. by a suction pad, to a curing station.

It will be appreciated that the above method is equally applicable where the projecting reinforcement portions are of other than loop shape, e.g. where they are straight, provided always that they can be fully accommodated in the slots 304. Similarly, the block 308 can be made of any other crushable or elastomeric material such as rubber, beaver board etc. if desired. In one variation, the material 317 is replaced by polystyrene strips positioned in the slot 304 to prevent ingress of the concrete therein during pressing.

In another embodiment (not illustrated) of the present invention the edge form or mould divider consists merely of an elongated rubber block capable of deforming under pressure so as to allow for simultaneous compression of the form or divider and the concrete In a further embodiment (FIG. 7), a mould divider in accordance with the present invention comprises a lower beam 400 extending into the hollow of an upper beam 402 with the external surfaces of the lower beam in sliding engagement with the internal surfaces of the upper beam. A plurality of compression springs (such as spring 404) extend between the inner top surface of the beam 402 and a recess 406 in the upper surface of the beam 404, the strength of the springs being so chosen relative to the weight of the beam 402 as normally to hold the mould divider in the disposition shown in FIG. 7. In operation, with the divider located on the concrete moulds the beam 402 is displaced by the concrete press towards the beam 400 against the action of the compression springs. At the end of the pressing stroke, the upper beam 402 may, for example, assume the position indicated by chain lines 408 in FIG. 7.

In another form of mould divider in accordance with the invention (FIG. 8), a top beam 410 of rectangular cross-section is separated from a similar (bottom) beam 412 by a block 414 of elastic material, such as rubber, capable of resilient deformation in use of the divider.

In yet another form of mould divider in accordance with the invention (FIG. 9), a top beam 416 of rectangular cross-section is separated from a similar (bottom) beam 418 by channelled separating pieces 420 enclosing between them a block 422 of crushable material, such as expanded polystyrene, capable of deformation in use of the divider. The block 422 must of course be renewed prior to each use of the divider.

In a further form of divider in accordance with the invention (FIG. 10), a top beam 424 of substantially plate form, is separated from a similar (bottom) beam 426 by a resilient tubular member 428 inflated for example with air or water. The beams 424, 426 have flanged portions at their inner edges designed to retain the member 428 in position during use. When the divider is under no-load conditions, the member 428 will tend to assume a shape approximating to that shown in FIG. 10. However in use, the resilient nature of the member 428 allows it to deform from this shape in response to the pressure exerted on the top beam 424 during the pressing process.

FIG. 11 shows an edge form in accordance with the present invention and comprising an upper beam 430 separated from a lower beam 432 by a block 434 of elastic material such as rubber. The beams 430 and 432 have flanged portions extending to one side of their adjacent surfaces so that the width of the block 434 is greater than the minimum width of the beams. In use this edge form is located in a mould as illustrated in FIG. 12 and pressure is simultaneously applied by the concrete press to the upper surface of concrete 436 and of the mould divider, thereby compacting the concrete mix and moving the beam 430 towards the beam 434 with consequent deformation of the elastic block 434. The edge form is then expelled from the mould together with the pressed concrete article and is subsequently removed from the article for example using the arrangement to be hereinafter described with reference to FIG. 15. The resulting shape of the edge face of the concrete article is shown in FIG. 13 from whence it will be seen that this face has upper and lower projections 438, 439, corresponding to the beam regions of minimum width, and a central region 440 corresponding to the. increased width of the divider provided by the flange portions of the beam and the deformed central elastic block. It willbe apparent from FIG. 14 that two such articles may be abutted end to end with their flange portions 438, 439 substantially in contact with one another and their central portions, spaced apart so that the irregular zones of these central portions corresponding to the presence of the form block 434, do not spoil the adjoining of the slabs.

In yet another form of mould divider in accordance with the present invention (FIG, 14) a lower beam 442 extends into the hollow of an upper beam 444 with the external surfaces of the lower beam in sliding engagement with the internal surface of the upper beam. The lower beam 442 is recessed at 450 anda piston and cylinder return arrangement 452 is located between the opposed surfaces of the beams 444 and 422, the cylinder of the arrangement being formed an integral with the lower beam, and the piston integral with the upper beam. In addition a retaining tension spring 454 is wrapped around the return arrangement 452, the strength of the spring and weight of the beam 444 being normally insufficient to move the mould divider from the position shown in FIG. 14. It will be understood that the arrangement shown in FIG. 14 will be repeated at least once'more elsewhere along the length of the divider.

In operation, with the divider located in the concrete mould, the beam 444 is displaced by the upper platen of the press towards the beam 442 against the retarding action of the damping arrangement 452, the spring 454 being effective to retain the divider in its compressed condition until it is required for further use. To expand the divider again, the cylinder is connected with a pressure source*(not shown) and the arrangement 452 extended against the action of the spring 454. In a variation of this embodiment, the arrangement 452 is replaced by a double-acting cylinder and accumulator system to produce either a pneumatic or a hydraulic spring locking device.

FIG. 15 shows a plan view of a framework 500 according to the present invention, the framework comprising essentially an outer frame 502 to which compressible edge forms or mould dividers 504 in accordance with any of the previous figures, are attached by a plurality of swinging links 506. It will be seen that each edge form (or mould divider) 504 has one short end face abutting with a long face of the next edge form, and an end portion of one of its long edge faces abutting with the short end face of another edge form. The links 506 are pivotally connected to the frame 502 and the dividers 504 thereby allowing motion of the edge form parallel to the adjacent limb of the frame, this movement being effected by actuators 508 which are pivotally connected between the free end of the edge form concerned and the opposite part of the frame. It will be appreciated, therefore, that the particular disposition of the edge forms relative to one another allows them to be moved in such a way that their inner edge faces will always provide a closed boundary of substantially rectangular shape.

In operation the frame 502 is located with the concrete mould, the appropriate mix is poured into the space defined by the inner edges of the edge forms 504,

and the upper platen of the press is moved downwards as shown in FIG. 16. As has been previously described inconnection with the earlier Figures, the collapsible nature of the edge forms will allow these to be compressed simultaneously with the mix in the mould when the present operation is completed. the upper platen is removed, the frame work 500 and the associated concrete article is expelled from the mould, and the actuator 508 are operated to free the edge forms 504 from the edges of the pressed article. It will be appreciated that at least in its initial stage, the movement of the edge forms 504 is substantially parallel to the sides of the pressed article thereby reducing the risk of damage being caused to the article by any adhesion which might otherwise occur between the still moist concrete and the edge forms.

It will be understood that an edge form is, in effect, functionally equivalent to /z of a mould divider so that the mould dividers of FIGS. 3 to 5, 14 and 7 to 11 for example, may be used in place of the edge forms of FIGS. 1, 2, ll, 15, and 16. Similarly, in some cases edge fonns may be used in place of mould dividers. Thus if a large opening is desired in the article (e.g., where a window opening is desired in a pressed concrete panel), then 4 edge forms (or 4 mould dividers) can be arranged within the mould to delimit the boundaries of the desired opening.

We claim:

1. A wall member which presents a surface for bounding at least one side of a material to be pressed between upper and lower platens of a press, said wall member comprising:

a first elongated beam member providing a first portion of said surface,

a second elongated beam member providing a second portion of said surface,

said first and second members being relatively moveable towards one another to permit a reduction in an overall dimension of said surface upon relative closing movement of said platens which results in compression of both said material and said wall member, and

means for causing said first and second members to substantially retain their relative positions at the end of a pressing operation but which will yet follow slight expansions of said material which may occur upon removal of platen pressure thereby causing said overall dimension of said surface to retain substantially the same compressed dimension as said material.

2. A wall member as in claim 1 wherein:

said second beam member includes a sealed recess vertically adjacent a long edge of said beam for receiving said first beam member thereinto upon relative closing movement of said platens without permitting any substantial ingress of the pressed material during a pressing operation, and

said means for causing comprises friction means dis posed at the upper edge of said recess which is urged by the pressure of said pressed material into sealing engagement with a side face of said first beam member for allowing a controlled nonresilient motion of said beam into said recess upon the application of vertical pressure to said wall member.

3. A wall member as in claim I further comprising:

a third elongated beam member disposed between said first and second beam members and providing a third portion of said surface.

4. A wall member as in claim 3 wherein:

said third beam member comprises inner inclined surfaces adjacent mating outer inclined surfaces on said first and second beam members,

said inclined surfaces being mechanically biased together in frictional engagement whereby vertical closure of said platens causes relative closing movement of said first and second beam members and a transverse accommodating movement of said third beam member with frictional sliding movement along said inclined surfaces thus resulting in substantially non-resilient overall compression of said wall member.

5. An apparatus for use in forming concrete articles comprising a compressible non-resilient wall member as in claim 1 and a press having upper and lower plat ens.

6. For use in forming concrete articles, an apparatus comprising:

a press having upper and lower platens,

a plurality of compressible and non-resilient wall members defining a collapsible mould between said upper and lower platens,

each of said wall members engaging between said upper and said lower platens and bounding one side of an article to be pressed between said platens, whereby a relative movement between said upper and lower platens is effective to press the article and compress said wall member,

a support structure for said compressible wall members,

attachment means movably connecting said wall members with said support structure, and

actuator means for said wall members such that operation of said actuator means moves said wall members relative to said support structure to define moulds of different shapes between said platens.

7. An apparatus as claimed in claim 6 including means whereby operation of said actuator means moves said partition members at least initially substantially in a lengthwise direction.

8. An apparatus as claimed in claim 7 wherein said wall members are arranged with one short face of each wall member adapted to abut with an end portion of one of the long edge faces of an adjacent wall member.

9. An apparatus as claimed in claim 8 wherein said support structure is an outer frame, said attachment means are provided by links pivotally connected between said wall members and said outer frame, and said actuator means are provided by piston and cylinder means acting between said outer frame and end faces of said wall members.

10. Apparatus for use in forming articles with a press having upper and lower platens, said apparatus comprising:

a compressible non-resilient wall member for engaging between said upper and lower platens and for bounding at least one side of an article to be pressed between said platens, whereby a relative movement between said upper and lower platens is effective to press the article and compress, said wall member said wall member comprising;

an elongated beam,

means defining a sealed recess vertically adjacent a long edge of said beam for receiving said beam thereinto upon relative closing movement of said platens without permitting the ingress of the pressed material during a pressing operation, and

friction means disposed at the upper edge of said recess which is urged by the pressure of said pressed material into sealing engagement with a side face of said beam for allowing a controlled non-resilient motion of said beam into said recess upon the application of vertical pressure to said wall member.

1 1. A reusable apparatus for use in forming materials by a pressing process performed between an upper and a lower platen of a press, said apparatus comprising:

a continuously compressible reusable wall member means structured to cooperate with and to be sup ported by the top surface of said lower platen such that said wall member means is adapted for insertion between said platens to define one side of an enclosed mould area within the said top surface of said lower platen and thereby to bound at least one side of material to be pressed within said mould area by said platens whereby said wall member is compressed with said material by a relative movement between said platens,

said wall member including a first beam, a second beam, and mechanical coupling means mechanically linking the first and second beams, the mechanical coupling means being reversibly movable over a range of different configurations corresponding to different beam to beam separations occurring during the pressing process and during reexpansion of the wall member to its original dimensions in readiness for a subsequent pressing process, and

said mechanical coupling means also including means for causing said wall member to be substantially non-resilient thus preventing damage to said material after said pressing process whereby said wall member means substantially retains the same compressed dimensions as said compressed material after said pressing process when said platens are moved away from one another.

12. A reusable apparatus for forming materials by a pressing process, said apparatus comprising:

a press having upper and lower platens, and a compressible non-resilient reusable wall member structured to cooperate with and to be supported by the top surface of said lower platen such that said wall member is adapted for engaging between said upper and lower platens to define one side of an enclosed mould area therebetween and within the top surface of said lower platen thus bounding at least one side of said material to be pressed between said platens, whereby a relative movement between said upper and lower platens is effective to press said material and to compress said wall member,

said wall member including a first beam, a second beam, and mechanical coupling means mechanically linking the first and second beams, the mechanical coupling means being reversibly movable over a range of different configurations corresponding to different beam to beam separations occurring during the pressing process and during reexpansion of the wall member to its original dimensions in readiness for a subsequent pressing process.

13. An apparatus as in claim 12 comprising:

a plurality of said wall members arranged to define an at least partly collapsible mould between said upper and lower platens.

l4. Reusable apparatus for use in forming articles with a press having upper and lower platens, said apparatus comprising:

a reusable wall member structured to cooperate with and to be supported by the top surface of said lower platen'such that said wall member is adapted for engaging between said upper and lower platens to define one side of an enclosed mould area therebetween and within the top surface of said lower platen thus bounding one side of an article to be pressed between said platens,

said wall member including compressible means for said wall member including first and second beams,

said compressible means including mechanical coupling means mechanically linking the first and second beams, the mechanical coupling means being reversibly movable over a range of different configurations corresponding to different beam to beam separations occurring during the pressing process and during re-expansion of the wall member to its original dimensions in readiness for a subsequent pressing process, and

said compressible means also including means causing it to be non-resilient for substantially preventing expansion of the wall in conformance with platen movements at the end of a pressing operation and for thereby discouraging undesired damage to edge surfaces of the just pressed and uncured article.

15. An apparatus as claimed in claim 14 in which there are a plurality of said wall members defining a collapsible mould between said upper and lower platens.

16. Apparatus for use in forming articles with a press having upper and lower platens, said apparatus comprising a wall member adapted for engaging between said upper and lower platens to define at least one side of an enclosed mould area therebetween and thus bounding at least one side of an article to be pressed between said platens,

said wall member including compressible means for causing said wall member to be continuously compressible simultaneously with said article upon relative closing movement between said platens thereby permitting varied arrangements of said wall member between platen surfaces to permit formation of correspondingly varied shapes and sizes of said article within said enclosed mould area, i

said compressible means also including means causing it to be non-resilient for substantially preventing expansion of the wall in conformance with platen movements at the end of a pressing operation and for thereby discouraging undesired damage to edge surfaces of the just pressed and uncured article, and I a rigid mould carried on said lower platen, said upper platen being adapted to enter said mould and said wall member being located in said mould to subdivide the mould into two separate regions.

17. An apparatus as claimed in claim 14 wherein the compressible wall member includes at least a portion of compressible material extending substantially from end to end of the wall member.

18. Apparatus for use in forming articles with a press having upper and lower platens, said apparatus comprising a wall member adapted for engaging between said upper and lower platens to define at least one side of an enclosed mould area therebetween and thus bounding at least one side of an article to be pressed between said platens,

said wall member including compressible means for causing said wall member to be continuously compressible simultaneously with said article upon relative closing movement between said platens thereby permitting varied arrangements of said wall member between platen surfaces to permit formation of correspondingly varied shapes and sizes of said article within said enclosed mould area, and

said compressible means also including means causing it to be non-resilient for substantially preventing expansion of the wall in conformance with platen movements at the end of a pressing operation and for thereby discouraging undesired damage to edge surfaces of the just pressed and uncured article,

said compressible wall member comprising,

a first beam,

asecond beam co-terminous with said first beam, and

a collapsible'spacer means located between adjacent faces of said first beam and said second beam.

19. An apparatus as claimed in claim 14 including control means effective to keep the width of the wall member substantially constant during compression of the wall member.

20. A wall member which presents a surface for bounding at least one side of a material to be pressed between upper and lower platens of a press, said wall member comprising:

a first elongated beam member providing a first portion of said surface,

a second elongated beam member providing a second portion of said surface,

said first and second members being relatively moveable towards one another to permit a reduction in an overall dimension of said surface upon relative closing movement of said platens which results in compression of both said material and said wall member,

means for causing said first and second members to substantially retain their relative positions at the end of a pressing operation but which will yet follow slight expansions of said material which may occur upon removal of platen pressure thereby causing said overall dimension of said surface to retain substantially the same compressed dimension as said material, wherein said second beam member includes a sealed recess vertically adjacent a long edge of said beam for receiving said first beam member thereinto upon relative closing movement of said platens without permitting any substantial ingress of the pressed material during a pressing operation, and wherein said means for causing comprises friction means disposed along said recess which is urged by the pressure of said pressed material into sealing engagement with a side face of said first beam member for allowing a controlled non-resilient motion of said beam into said recess upon the application of vertical pressure to said wall member.

21. Apparatus for use in forming articles with a press having upper and lower platens, said apparatus comprising:

a compressible non-resilient wall member for engaging between said upper and lower platens and for friction means disposed along said recess which is urged by the pressure of said pressed material into sealing engagement with a side face of said beam for allowing a controlled non-resilient motion of said beam into said recess upon the application of vertical pressure to said wall member.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3, 822 979 I V Dated a x 9 I i J 914 Inventods) Eugene Francis O'Sullivan et al It is certified that error appears in the aboveidentified patent and that said Letters Patent are hereby corrected as shown below:

After item [21] on the cover sheet, insert:

-[30] Foreign Application Priority Data October 6, 1967 Great Britain.....45926 May 30, 1968 Great Britain. ..25989-- Signed and sealed this 8th day of October 1974.

, (SEAL) Attest:

MCCOY M. GIBSON JR. C. MARSHALL DANN Attesting Officer Commissioner of Patents F 9 RM Po no 6 USCOMM-DC 00370-P69 

1. A wall member which presents a surface for bounding at least one side of a material to be pressed between upper and lower platens of a press, said wall member comprising: a first elongated beam member providing a first portion of said surface, a second elongated beam member providing a second portion of said surface, said first and second members being relatively moveable towards one another to permit a reduction in an overall dimension of said surface upon relative closing movement of said platens which results in compression of both said material and said wall member, and means for causing said first and second members to substantially retain their relative positions at the end of a pressing operation but which will yet follow slight expansions of said material which may occur upon removal of platen pressure thereby causing said overall dimension of said surface to retain substantially the same compressed dimension as said material.
 2. A wall member as in claim 1 wherein: said second beam member includes a sealed recess vertically adjacent a long edge of said beam for receiving said first beam member thereinto upon relative closing movement of said platens without permitting any substantial ingress of the pressed material during a pressing operation, and said means for causing comprises friction means disposed at the upper edge of said recess which is urged by the pressure of said pressed material into sealing engagement with a side face of said first beam member for allowing a controlled non-resilient motion of said beam into said recess upon the application of vertical pressure to said wall member.
 3. A wall member as in claim 1 further comprising: a third elongated beam member disposed between said first and second beam members and providing a third portion of said surface.
 4. A wall member as in claim 3 wherein: said third beam member comprises inner inclined surfaces adjacent mating outer inclined surfaces on said first and second beam members, said inclined surfaces being mechanically biased together in frictional engagement whereby vertical closure of said platens causes relative closing movement of said first and second beam members and a transverse accommodating movement of said third beam member with frictional sliding movement along said inclined surfaces thus resulting in substantially non-resilient overall compression of said wall member.
 5. An apparatus for use in forming concrete articles comprising a compressible non-resilient wall member as in claim 1 and a press having upper and lower platens.
 6. For use in forming concrete articles, an apparatus comprising: a press having upper and lower platens, a plurality of compressible and non-resilient wall members defining a collapsible mould between said upper and lower platens, each of said wall members engaging between said upper and said lower platens and bounding one side of an article to be pressed between said platens, whereby a relative movement between said upper and lower platens is effective to press the article and compress said wall member, a support structure for said compressible wall members, attachment means movably connecting said wall members with said support structure, and actuator means for said wall members such that operation of said actuator means moves said wall members relative to said support structure to define moulds of different shapes between said platens.
 7. An apparatus as claimed in claim 6 including means whereby operation of said actuator means moves said partition members at least initially substantially in a lengthwise direction.
 8. An apparatus as claimed in claim 7 wherein said wall members are arranged with one short face of each wall member adapted to abut with an end portion of one of the long edge faces of an adjacent wall member.
 9. An apparatus as claimed in claim 8 wherein said support structure is an outer frame, said attachment means are provided by links pivotally connected between said wall members and said outer frame, and said actuator means are provided by piston and cylinder means acting between said outer frame and end faces of said wall members.
 10. Apparatus for use in forming articles with a press having upper and lower platens, said apparatus comprising: a compressible non-resilient wall member for engaging between said upper and lower platens and for bounding at least one side of an article to be pressed between said platens, whereby a relative movement between said upper and lower platens is effective to press the article and compress, said wall member said wall member comprising; an elongated beam, means defining a sealed recess vertically adjacent a long edge of said beam for receiving said beam thereinto upon relative closing movement of said platens without permitting the ingress of the pressed material during a pressing operation, and friction means disposed at the upper edge of said recess which is urged by the pressure of said pressed material into sealing engagement with a side face of said beam for allowing a controlled non-resilient motion of said beam into said recess upon the application of vertical pressure to said wall member.
 11. A reusable apparatus for use in forming materials by a pressing process performed between an upper and a lower platen of a press, said apparatus comprising: a continuously compressible reusable wall member means structured to cooperate with and to be supported by the top surface of said lower platen such that said wall member means is adapted for insertion between said platens to define one side of an enclosed mould area within the said top surface of said lower platen and thereby to bound at least one side of material to be pressed within said mould area by said platens whereby said wall member is compressed with said material by a relative movement between said platens, said wall member including a first beam, a second beam, and mechanical coupling means mechanically linking the first and second beams, the mechanical coupling means being reversibly movable over a range of different configurations corresponding to different beam to beam separations occurring during the pressing process and during reexpansion of the wall member to its original dimensions in readiness for a subsequent pressing process, and said mechanical coupling means also including means for causing said wall member to be substantially non-resilient thus preventing damage to said material after said pressing process whereby said wall member means substantially retains the same compressed dimensions as said compressed material after said pressing process when said platens are moved away from one another.
 12. A reusable apparatus for forming materials by a pressing process, said apparatus comprising: a press having upper and lower platens, and a compressible non-resilient reusable wall member structured to cooperate with and to be supported by the top surface of said lower platen such that said wall member is adapted for engaging between said upper and lower platens to define one side of an enclosed mould area therebetween and within the top surface of said lower platen thus bounding at least one side of said material to be pressed between said platens, whereby a relative movement between said upper and lower platens is effective to press said material and to compress said wall member, said wall member including a first beam, a second beam, and mechanical coupling means mechanically linking the first and second beams, the mechanical coupling means being reversibly movable over a range of different configurations corresponding to different beam to beam separations occurring during the pressing process and during re-expansion of the wall member to its original dimensions in readiness for a subsequent pressing process.
 13. An apparatus as in claim 12 comprising: a plurality of said wall members arranged to define an at least partly collapsible mould between said upper and lower platens.
 14. Reusable apparatus for use in forming articles with a press having upper and lower platens, said apparatus comprising: a reusable wall member structured to cooperate with and to be supported by the top surface of said lower platen such that said wall member is adapted for engaging between said upper and lower platens to define one side of an enclosed mould area therebetween and within the top surface of said lower platen thus bounding one side of an article to be pressed between said platens, said wall member including compressible means for causing said wall member to be continuously compressible simultaneously with said article upon relative closing movement between said platens thereby permitting varied arrangements of said wall member between platen surfaces to permit formation of correspondingly varied shapes and sizes of said article within said enclosed mould area, said wall member including first and second beams, said compressible means including mechanical coupling means mechanically linking the first and second beams, the mechanical coupling means being reversibly movable over a range of different configurations corresponding to different beam to beam separations occurring during the pressing process and during re-expansion of the wall member to its original dimensions in readiness for a subsequent pressing process, and said compressible means also including means causing it to be non-resilient for substantially preventing expansion of the wall in conformance with platen movements at the end of a pressing operation and for thereby discouraging undesired damage to edge surfaces of the just pressed and uncured article.
 15. An apparatus as claimed in claim 14 in which there are a plurality of said wall members defining a collapsible mould between said upper and lower platens.
 16. Apparatus for use in forming articles with a press having upper and lower platens, said apparatus comprising a wall member adapted for engaging between said upper and lower platens to define at least one side of an enclosed mould area therebetween and thus bounding at least one side of an article to be pressed between said platens, said wall member including compressible means for causing said wAll member to be continuously compressible simultaneously with said article upon relative closing movement between said platens thereby permitting varied arrangements of said wall member between platen surfaces to permit formation of correspondingly varied shapes and sizes of said article within said enclosed mould area, said compressible means also including means causing it to be non-resilient for substantially preventing expansion of the wall in conformance with platen movements at the end of a pressing operation and for thereby discouraging undesired damage to edge surfaces of the just pressed and uncured article, and a rigid mould carried on said lower platen, said upper platen being adapted to enter said mould and said wall member being located in said mould to sub-divide the mould into two separate regions.
 17. An apparatus as claimed in claim 14 wherein the compressible wall member includes at least a portion of compressible material extending substantially from end to end of the wall member.
 18. Apparatus for use in forming articles with a press having upper and lower platens, said apparatus comprising a wall member adapted for engaging between said upper and lower platens to define at least one side of an enclosed mould area therebetween and thus bounding at least one side of an article to be pressed between said platens, said wall member including compressible means for causing said wall member to be continuously compressible simultaneously with said article upon relative closing movement between said platens thereby permitting varied arrangements of said wall member between platen surfaces to permit formation of correspondingly varied shapes and sizes of said article within said enclosed mould area, and said compressible means also including means causing it to be non-resilient for substantially preventing expansion of the wall in conformance with platen movements at the end of a pressing operation and for thereby discouraging undesired damage to edge surfaces of the just pressed and uncured article, said compressible wall member comprising, a first beam, a second beam co-terminous with said first beam, and a collapsible spacer means located between adjacent faces of said first beam and said second beam.
 19. An apparatus as claimed in claim 14 including control means effective to keep the width of the wall member substantially constant during compression of the wall member.
 20. A wall member which presents a surface for bounding at least one side of a material to be pressed between upper and lower platens of a press, said wall member comprising: a first elongated beam member providing a first portion of said surface, a second elongated beam member providing a second portion of said surface, said first and second members being relatively moveable towards one another to permit a reduction in an overall dimension of said surface upon relative closing movement of said platens which results in compression of both said material and said wall member, means for causing said first and second members to substantially retain their relative positions at the end of a pressing operation but which will yet follow slight expansions of said material which may occur upon removal of platen pressure thereby causing said overall dimension of said surface to retain substantially the same compressed dimension as said material, wherein said second beam member includes a sealed recess vertically adjacent a long edge of said beam for receiving said first beam member thereinto upon relative closing movement of said platens without permitting any substantial ingress of the pressed material during a pressing operation, and wherein said means for causing comprises friction means disposed along said recess which is urged by the pressure of said pressed material into sealing engagement with a side face of said first beam member for allowing a controlled non-resilient motion of said beam into said recess upon the appLication of vertical pressure to said wall member.
 21. Apparatus for use in forming articles with a press having upper and lower platens, said apparatus comprising: a compressible non-resilient wall member for engaging between said upper and lower platens and for bounding at least one side of an article to be pressed between said platens, whereby a relative movement between said upper and lower platens is effective to press the article and compress, said wall member said wall member comprising; an enlongated beam, means defining a sealed recess vertically adjacent a long edge of said beam for receiving said beam thereinto upon relative closing movement of said platens without permitting the ingress of the pressed material during a pressing operation, and friction means disposed along said recess which is urged by the pressure of said pressed material into sealing engagement with a side face of said beam for allowing a controlled non-resilient motion of said beam into said recess upon the application of vertical pressure to said wall member. 